title: [Optimal TRH-testdose in children: 1 microgram TRH/kg (i. v.) (author's transl)].
abstract: In a previous study the optimal TRH test dose of 1 microgram/kg (i v.) was determined in 67 infants between the ages of 2 weeks and 2 years old. At that time the following doses were tested: 0.5 microgram, 1 microgram, 1 microgram/kg, 2 micrograms/kg and 200 micrograms. In the present study the clinical application of this low dose TRH administered to children between the ages of 25 months and 16 years will be reported. There was a significant increase in TSH in all of the 70 euthyroidic children. The 30 minute values after intravenous injection of 1 microgram TRH/kg were 11.7 +/- 4.5 microU/ml (400% increase, upper threshold value 20 microU/ml). The dose of 200 micrograms TRH resulted in a 30 min value of 13.0 +/- 6.6 microU/ml in 30 of the children (430% increase, upper threshold value 20 microU/ml). In children two years old and younger these values were significantly higher. After administering 1 micrograms TRH/kg, the value 17.0 +/- 8.5 microU TRH/ml was measured in 20 children (735--400% increase) and after 200 micrograms TRH, the value 21.0 +/- 7.5 microU/ml (690--200%). The upper threshold value is 36 microU TSH/ml. The TSH basal secretion did not depend on the age of the child. The upper threshold value of 7.5 microU TSH/ml applies to children two weeks of age and older. 1 microgram TRH/kg (i. v.) is the optimal test dose for children. The higher doses do not provide any additional clinical information.
mesh_terms: D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006980:Hyperthyroidism / Q000175:diagnosis; D007037:Hypothyroidism / Q000175:diagnosis; D007223:Infant; D007275:Injections, Intravenous; D013972:Thyrotropin / Q000097:blood; D013973:Thyrotropin-Releasing Hormone
chemical_list: D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin
vernacular_title: Optimale TRH-Testdosis bei Kindern: 1 microgram TRH/kg (i. v.). Normalwerte bei euthyreoten Kindern.